Field of the Invention
The present invention disclosure relates to the removal of cations from a substance stream produced during the production of isophoronenitrile with the help of a cation exchanger.
Discussion of the Background
The base-catalyzed reaction of hydrocyanic acid (HCN) with alpha,beta-unsaturated cyclic (or acyclic) ketones is a known reaction (Hydrocyanation of Conjugated Carbonyl Compounds, CHAPTER 3, Wataru Nagata and Mitsuru Yoshioka, Wiley 2005).
EP 2 721 002 discloses numerous processes for the preparation of isophoronenitrile, see the documents cited therein.
EP 2 649 043 describes a process for the preparation of isophoronenitrile. For the removal of the catalyst, the following documents are cited:
According to JP 06065182, after the reaction of HCN with IP has been carried out, the alkaline catalyst can be neutralized and the reaction mixture worked up directly in the distillation.
Alternatively, according to JP 06065183, the alkaline reaction mixture can be mixed with an inert solvent and worked up in a thin-film evaporator. This removes the catalyst, the high boilers and the solvent. The resulting isophoronenitrile is then purified in a further column.
The catalyst can be removed, for example, by the processes described in DE 10 85 871 or EP 433 615.
Isophoronenitrile (IPN) is produced by the reaction of isophorone (IP) with hydrocyanic acid with the assistance of a catalyst. Preferably, homogeneous base catalysis is used, for this alkali metal alcoholates, in particular sodium methanolate, are used as catalyst, as described in EP 2649043.